The telecommunications industry employs many miles of cable for low frequency transmissions. Recent trends in this industry have dictated that signal contacts are designed to be closer together than previously. This shortens the signal transmission pass between signal contacts and reduces the amount of space occupied by the contact spacing. Unfortunately, if the signal contacts are close together, they can be electrically coupled inductively and capacitively to produce cross-talk and stray voltages. One prior art attempt to minimize these effects by separating rows of signal contacts with reference contact plates is described in U.S. Pat. No. 4,984,992, which is incorporated herein by reference.
During an electrical signal transmission, pulses are sent along parallel circuit paths and the magnitude of the differences between these paths is measured in deciphering the signal. Since separately shielded signal wires can be affected somewhat differently by electrical interferences over the many miles of transmission, pulses can be changed beyond allowable tolerance levels.
In an effort to avert the inductive and electrostatic variances between parallel pulse lines of digital switching applications, "differential pair" conductors have been designed which include a pair of connector wires insulated from one another and shielded with a metallic braiding. The ends of the differential pair typically include an adapter connected to the differential pair cable with a braided PIC termination and insulation strain relief. Since both connector wires of the differential pair are identically and commonly insulated and conductively-shielded from electrical interference, they produce the same response to inductive and electrostatic effects, thereby providing an accurate differential magnitude for more reliable signal deciphering.
Because differential pairs are a relatively new connector element, connector housings, and the like, must be equipped to accommodate them in a highly reliable and efficient fashion. Accordingly, a need exists for cable connector systems which provide means for using differential pairs with currently employed low frequency connectors and reference elements for eventually connecting to mating portions on a printed circuit board, such as the posts of a pin field connector. Such systems must both conserve space and minimize noise and cross-talk.